We see new baby birds, but also a little white sac. This is called a fecal sac, and it's really important!

Baby robins are in their nest for about 13 days. The nestlings poop just about every time they gulp down some food. Let's see—that's 13 days x 4 babies x 356 insects and worms on average each day. That's a LOT of poop! How on earth do robins keep their nest clean?

Baby robins produce their poop in fecal sacs, encased in strong membranes that don't leak. The parents pick up the sacs in their beak and carry them away from the nest. Fecal sacs are like disposable diapers for birds!